Johnson 2hp lean screw- broken?

[mdfan]

I have a 82 Johnson 2hp I bought at a yard sale.

The low idle screw does not have a point on the end, like a pencil. Its square and hollow. The high idle screw has a point on the end, as I would expect.

I found a schematic on Johnson's website and it appears the low should be similar to the high screw. I looked into the carb where the low screws in, and see a small brass post like thing in there,and it doesnt rattle around nor will it fall out.

Im not sure if this is the way its designed, or something is broken. Can anyone answer this question?

If needed, ill upload a photo.

Thanks in advance.

 

[tashasdaddy]

Re: Johnson 2hp lean screw- broken?

it should be pointed, the tip is broken. it could be in the orifice, from over tightening. you need to order the needle, and a carb kit. the reason is the only way to tell if the tip is in the orifices, is to remove the core plug on top of the carb. and look thur the orifice, and see light.

 

[mdfan]

Re: Johnson 2hp lean screw- broken?

Thanks for the feedback. I guess thats good and bad news- need to figure out a way to get it out. I imagine its just friction holding it in- ill bathe it in carb cleaner and try to wiggle with a small screwdriver.

 

[tashasdaddy]

Re: Johnson 2hp lean screw- broken?

http://forums.iboats.com/showthread.php?t=244013

 

[mdfan]

Re: Johnson 2hp lean screw- broken?

The core plug- how do you remove and install them? ITs the plug that appears pressed in, correct? Ive rebuilt carbs before but never messed with one. They are a mystery to me but im sure they are simple if you know what to do

 

[tashasdaddy]

Re: Johnson 2hp lean screw- broken?

i take an ice pick, punch thru the center just enough to pry it out. then to install i set the new one in place, take a 3/8 or 1/4 in ratchet extention, and place the blunt end on the plug, and a couple of light taps with a hammer. i also have a board with a hole drilled in it, to insert the pick up tube so the carb lays flat.

 

[mdfan]

Re: Johnson 2hp lean screw- broken?

So the core plug is just pressed in? What is its purpose- just a cover, or cap? Its round, so wouldnt something like a wood dowel be appropriate?
Im just nervous about removing it- there is no turning back after the ice pick attack.
I cant get the broken tip of the screw to even move- its perfectly centered and doesnt budge when try to move it with a allen wrench. Im really questioning if its supposed to be there.
Ive attached photos of the low and high screw

 

[tashasdaddy]

Re: Johnson 2hp lean screw- broken?

ok, you've got me, i've never seen on like the top one. requesting more help.

 

[Xcusme]

Re: Johnson 2hp lean screw- broken?

As tashasdaddy has said...use a sharp ice pick and pry it out, it's no big deal. The core plug is a cover for a small chamber leading to the idle ports into the carb throat. The replacement core plug is convex. Install the new one with the domed side up. When you flatten the dome of the plug, it will expand into the opening and effect a seal. Once you do it, you'll wonder what all the worry was about. Most seasoned guys will caution you not to go too deep into the plug with the pick. There's a cavity underneith the plug approx. 1/4"deep, so there's plenty of room for the pick.
Forget trying to use a wooden plug, the one that comes in the kit is made to fit and is easy to remove and install.

When you have the old plug out, you should see the tip of the broken needle valve. Insert a tool to push the pointed end of the broken needle valve out of the hole. The broken tip should fall out of the threaded hole for the needle valve.

 

[mdfan]

Re: Johnson 2hp lean screw- broken?

I was thinking of the dowel to set the plug, not as a plug.

So do you think my screw is broken? The fact its hollow, and it looks like the piece inside would fit inside the recess makes me think its designed that way.

 

[Xcusme]

Re: Johnson 2hp lean screw- broken?

Duuh, sorry, yes a dowel would be just fine. Actually, if using a 1/4 or 3/8 ratchet extention, you have to be a bit careful seating the plug as the end of the extension is slightly rounded and can over seat the plug (making it too concave) . I've used both a dowel and ratchet extension, just go until it's flat and you'll be fine.

Yea, I noticed that it appears that the end of that needle had a pointed insert installed. Perhaps the insert was held into the threaded shaft with an interference fit (shaft heated, tip inserted, then cooled). If that was the case, and you do recover the tip, I'd personally clean all and solder it back into place. This depends on the condition of the tip etc. A replacement needle may be you only option too, your call.

 

[F_R]

Re: Johnson 2hp lean screw- broken?

Wow, must be the slow speed needle was a two piece affair and the end came out of the outer, threaded part. I'm guessing the pointed end part is made of steel. Just a guess. I haven't seen one exactly like that before, but I've seen plenty of them where the tip of the (brass) needle was broken off up inside the carb from somebody screwing it in too far/tight.

Like everybody has been telling you, remove the core plug and see if you can knock the piece out of the hole. I don't mean to alarm you, but I've seen them where I couldn't get the tip out and had to drill a hole in the chamber, opposite the needle tip, giving access to get a straight shot at it with a hammer and skinny punch. Then of course there is the hole to plug up with a lead shot or something. Mind you, this is a last ditch effort to save an otherwise junk carb.

Somebody said that you will be told to be careful driving an ice pick in too far. Yep, I'm telling you that. As long as you are careful you will be OK, but just so you know. Actually, I use a small pin punch instead of an ice pick. But that's just me, I guess.

 

[mdfan]

Re: Johnson 2hp lean screw- broken?

Ive written the how to guide for the next person with this issue
1. wiggle the broken tip arount with something- needle nose pliers, for example
2. unsuccessfully try to poke thru orifice with said needle nose pliers
3. get more motivation and get up to go to garage for awl
4. yawn and stretch on way to garage
5. tip will fall out on floor- find it and the job is done

ive attached a photo. Think ill J & B weld it to the brass screw.

 

[R.Johnson]

Re: Johnson 2hp lean screw- broken?

The advice from FR will solve your problem, I have done this several time's. Otherwise, you are looking at a new carb body.

 

[Joe Reeves]

Re: Johnson 2hp lean screw- broken?

The solutions above are great. I have also had luck by defacing the inside of that hollow brass portion of the needle valve with a center punch, pointed scribe, etc, then screwing it into the carburetor so that the stuck portion of the needle valve is inserted into the hollow portion...... then backing it out. The inner irregular defaced walls of the hollow portion grabs the stuck piece and backs it out. Sometimes it works, sometime it doesn't, but that's where I'd start.

 

[Xcusme]

Re: Johnson 2hp lean screw- broken?

Mdfan, you might find the JB Weld a bit heavy for this application. I'd clean both parts with Acetone and Super Glue them together, but work fast, the clearances are small and the glue grabs fast. Personally , I'd insert the tip completely leaving only a very tiny gap from fully seated and apply the glue. Capillary action will pull the right amount into the joint, then seat tip.

 

[tashasdaddy]

Re: Johnson 2hp lean screw- broken?

will i learned something.